And it will accelerate as I expect it. The worst threats isn't storms droughts tornadoes. To me it's the oceans acidity increasing, and it's ability to take up CO2 diminishing. The food fish we eat will disappear, as the reefs they use. The plankton are already diminished, with their demise around the corner as I see it. When that happens we have destroyed the oceans first food chain, and the effects that bear on all trusting in that food will come to haunt us as the ripples widen. When they are gone the process they make of taking up and disposing of CO2 will also disappear leaving a lot more CO2 in the ocean making its acidity accelerate. All living things 'live' on each other, the shoes you use, the food you eat, it all come from somewhere. Destroying the food chain we also destroy our children's future.

This one is a little old, and it doesn't mention it all, but it's still interesting.Oceans Reflux.

You need to first ask what weather patterns Joe is talking about, and perhaps where he is.

Such a knee-jerk reaction to blame everything on "Global Warming" and "CO2" is a disservice to climatology science, and the argument in general.

Great Britain and Europe had 100 year low temperatures last winter. Perhaps you could argue that it was unseasonably mild and that one would have expected 200 year lows without global warming. However, please be very careful blaming snow and ice on warm weather.

Again... record snowfalls are generally not attributable to global warming.

The cold weather that much of Europe and North America had this last year has to do with Arctic Weather Patterns which essentially create weather patterns shifting warmer air northward (relatively speaking) and cold weather southward.

There was discussion of "Blocking Patterns" earlier which may be attributable to weak solar cycles (more on that later). There was also a strong negative Arctic Oscillation (AO) last winter.

Average sea surface temperatures for the last 12 months have been very neutral. Again, the question might be whether one would have expected them to be colder.

Since mid-2010 we've been in an La Niña dominated ocean current pattern.Note the big blue "arrow" west of Central America.

It has actually weakened over the last couple of months, with now a warm area extending along the equator with a quite a warm area near Panama and Peru.

The La Niña weather patterns control much of the actual weather around the Pacific, and even into the Atlantic.

However, there are some other sea surface patterns too. Note the blue area extending up along the Pacific Coast of North America and towards Alaska. While somewhat related to the La Niña temperatures, it is considered a separate phenomenon called Pacific Decadal Oscillation (PDO).http://jisao.washington.edu/pdo/

We also seem to be in a warm Atlantic Multidecadal Oscillation (AMO) sea surface pattern which brings warm water to the North Atlantic, although it may have weakened somewhat in the last year or so. The AMO was negative from the mid 60's to mid 90's, and shifted positive in the late 90's. It could continue in the warm phase for another decade or two.

Anyway, in Oregon, we've had temperatures that have been below normal almost every day for the last 2 or 3 months, with daily average temperatures in the range of 5°F below average. I'm certainly not blaming that on Global warming, but rather on La Niña and the cold PDO.

This cold North Pacific along with the Arctic Weather Patterns and warm South Atlantic are creating some wicked temperature extremes across the USA and spawning many viscous tornadoes.

When you look at the tornado statistics, initially it may appear as if we are having an increasing number of occurrences. However, there is a large reporting bias with the weaker tornadoes, due to better detection equipment and better reporting, and perhaps increasing urbanization. This is especially noted with the weakest of the tornadoes.

Clifford I've had this debate for five years now and I'm telling Joe exactly what I expect. That you, or for that sake me too, don't like it has nothing to do with what I expect. I wouldn't expect it if I didn't believe that I'm right here. The results of the Climate changing will be what I say. We are fast going for a tipping point, or possibly already past one. And I never liked lies.==

I am surprised to hear people in the scientific world expressing doubt about Global Warming. I had thought that it was a generally accepted fact. Are you guys really on the other side of the argument or are you just playing Devil's advocate? Thanks for comments. Joe L. Ogan

Don't know about that :)But I got Joe's question alright. He's wondering about what I'm wondering about too. Nowadays I look at the weather expecting the unexpected every day :) We had some 'tromb's' (tornadoes) it seems today, very unusual, in the wrong part of the country, and at the wrong time of year too.

I expect such things to become more, freaky weather, with storms becoming stronger, not necessarily more of them, even though I myself think so, but definitely stronger. Cat 5 will become usual in the next decades. Snow where no snow been seen and droughts in other places. The ocean already moves faster due to the heat magazined in it.

We should distinguish between "weather" and "climate". Weather can be, locally, very variable on both a short and longer term so Clifford is right to ask for clarification as to the meaning of the original question. On the other hand it is fair to say there is wide agreement that the climate is changing on a worlwide scale and that a large majority now agree it is due to global warming.

There are still disagreements as to the causes of the global warming and it seems apparant that the original deniers of global warming have now just backed off (in the face of irrefutable evidence) to the position of "well OK, but it's not man-made". Whilst this is a perfectly respectable position to take, it does sound like they made a decision based on a political position and are unwilling to change their minds. It is interesting how popular opinion within countries follows the interests of their countries' main fiscal requirements. There are obvious cases but a good example is Canada where one might expect an ultra-green attitude from a country with such huge natural resources for clean power production. In fact Canada, and a majority of Canadians, are not supporters of the cause of global warming to be due to CO2. This view is more understandable when you realise that Canada is a huge exporter of oil, mainly to the USA (it is also the USA's biggest supplier). It is surprising how much national interests influences individuals' views on scientific evidence which few would understand. This certainly speaks volumes about how independently we all think about a whole variety of subjects.

Global warming affects local weather in ways that are not obvious. It does not mean that everywhere is warmer for example. If the Gulf Stream shuts down Northern Europe will end up with much colder winters for example. One thing that will happen is that weather patterns will generally have more energy in them, so there will be more extremes - stronger winds, heavier rain (when there is rain), more snow (where it snows) and it may be we are seeing some of this but it is possibly too early to be sure. Rising sea levels will be a huge problem but we won't see the consequences of this for some decades.

While Canada and Russia risk huge climate changes, the countries also would likely reap benefits from global warming. Thus, it is not just oil concerns in Canada, but they also have bitter cold winters.

However, again the question was ill defined.

As far as weather. The USA has been hammered by tornadoes this year.

Look at the NOAA graph and one sees a pattern of increasing tornadoes.

You might be struck by the count jumping from about 200 in 1950 to over 1200 in 2010. a six-fold increase.

However, there are many articles indicating that more of the weak tornadoes are being detected now than had happened in the past. I.E. We now are close to the technology to detect every single dust devil.

If you only look at the stronger tornadoes (F3 to F5), one sees a much different picture.

One might actually be tempted to conclude that the warmer weather brings fewer or weaker tornadoes to the USA.

My guess is that prior to 1980, a lot of weak tornadoes went unreported, but some were reported as being stronger than they actually were, and the true trend is much flatter than presented in either graph.

The hurricane trends are a bit more difficult to define as the annual number are much lower, especially with the stronger Category 4&5 hurricanes. So, much of the predictions of more stronger hurricanes is still in the realm of theory rather than observations.

As mentioned, Great Britain is somewhat unique in that it lies at the same latitude as much of Canada, as well as Russia, and even extends as far north as Southern Alaska. Temperatures are more mild than would otherwise be expected due to the gulf stream.

A collapse of the gulf stream would be hard on Great Britain. However, two years worth of harsh winters don't indicate an imminent gulf stream collapse. It is believed that it has slowed in the past only as a response to a catastrophic dumping of freshwater into the Arctic Ocean, much faster than the oceans could mix the fresh/salt water, and much faster than we are seeing with gradual glacier melt.

However, there are many articles indicating that more of the weak tornadoes are being detected now than had happened in the past. I.E. We now are close to the technology to detect every single dust devil.

I think you could be right about that. About twenty years ago we experienced an event in NJ. There was a path of destruction no more than 100 yards wide that ran right across our town. It uprooted some huge trees and dumped them on a house on our street about four houses from ours, while there was hardly a leaf out of place at our place.

It was obviously the result of a small tornado, but I don't think it was ever declared as such. I think they might have said something along the lines of a "funnel cloud" had touched down.

Clifford, the plots are interesting and it certainly would not be too surprising that some aspects of statistics are biassed by the limitations of precision of past equipment. I do have a problem with taking for granted statements from Dr Spencer though. Like I said before, it seems that this debate is based on political belief and then fitting the science to suit and he is a prime example, even though he is one of the more well qualified people in the ranks.

As believer in intelligent design he goes down a few notches in my estimation. He holds the view that global warming is not man made. He also says that variation in cloud cover provides negative feedback and that the IPCC models are wrong. He therefore denies that there is a significant problem with global warming at all, though he is slightly less dogmatic on this issue.

It seems another case of believing the climate scientist that supports one's own prejudices. It should be noted that the majority of climate scientists do not agree with Dr Spencer. Despite this, and because it has become (in the USA) a conservative vs liberal debate, the science has taken a back seat with just selected views being pulled out to support preformed opinion.

Thanks Clifford. As I said, this does not surprise me and think this is quite believable. The problem is that it is a "straw man" argument against global warming. If the argument has been used that the number of tornados in the USA has increased in recent times (the last 20 years) in a way to show the effects of global warming then this is rather poor science and it should not have been used in this way. Again it is looking at "weather" rather than "climate" and the timescales are not really long enough to form an opinion. We should rather be looking at changes since (say) 1850. I notice, for example, that F1, F2 and F3 tornados showed an increase from 1950 to 1973. It is always difficult to rely on measurements when the baseline methods have changed.

Globally (not just in the North Atlantic), there is an average of about 90 tropical storms every year. According to the 2007 Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC-AR4), globally "[t]here is no clear trend in the annual numbers [i.e. frequency] of tropical cyclones."

However, in the North Atlantic there has been a clear increase in the frequency of tropical storms and major hurricanes. From 1850-1990, the long-term average number of tropical storms was about 10, including about 5 hurricanes. For the period of 1998-2007, the average is about 15 tropical storms per year, including about 8 hurricanes. This increase in frequency correlates strongly with the rise in North Atlantic sea surface temperature, and recent peer-reviewed scientific studies link this temperature increase to global warming. ===

But while the numbers are not contested, their significance most certainly is. Another study considered how this information was being collected, and research suggested that the increase in reported storms was due to improved monitoring rather than more storms actually taking place.

I certainly would have to question a study that finds 100% of the effect during a single decade, or part thereof from about 2000 to 2007. It certainly doesn't show much of a linear trend.

In fact, you should also average in about a 20 year period from 1970 to 1990 that seemed to have lower than average tropical storms.

Reading through the comments, there are a lot of questions on whether there are significant differences in the number and intensity of storms actually making landfall which would lead me to believe that some of the increasing number would be due to better tracking of storms in the middle of the oceans.

If warming is a global phenomenon, then we should be looking at global storms.

Yep Clifford, I agree, there are a lot of interesting comments. And I recommend you for reading them :) I always look at the comments myself. But to make it short, I stand on the side of them, that really believe that there is a trend :)==

Globally (not just in the North Atlantic), there is an average of about 90 tropical storms every year. According to the 2007 Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC-AR4), globally "[t]here is no clear trend in the annual numbers [i.e. frequency] of tropical cyclones."

However, in the North Atlantic there has been a clear increase in the frequency of tropical storms and major hurricanes. From 1850-1990, the long-term average number of tropical storms was about 10, including about 5 hurricanes. For the period of 1998-2007, the average is about 15 tropical storms per year, including about 8 hurricanes. This increase in frequency correlates strongly with the rise in North Atlantic sea surface temperature, and recent peer-reviewed scientific studies link this temperature increase to global warming. ===

Nice plot, but is it statistically significant? If you pick at data enough you can find some subset that shows a line going in the direction you want. That doesn't necessarily mean it's significant.

I'm not arguing against working to slow or halt climate change. I think it's going to cause major problems, and possibly an increase in frequency or severity of storms. The plot might show a real phenomena that will get worse. I just haven't seen a convincing case for it yet.

The Naked Scientists® and Naked Science® are registered trademarks.
Information presented on this website is the opinion of the individual contributors
and does not reflect the general views of the administrators, editors, moderators,
sponsors, Cambridge University or the public at large.